The invention relates to a coupling device between a first mechanism having a stator and a rotor and a second mechanism having a stator and a rotor, in which all stators and rotors have the same geometrical axis, and the stator of the second mechanism can be turned around the geometrical axis relative to the stator of the first mechanism.
In this specification and in the accompanying claims, the terms stator and rotor must not be understood in an absolute sense. By rotor is understood an element that can be turned relative to the stator about the common geometrical axis, without necessarily being permitted to turn through the full 360.degree.. Also, the term stator does not mean that this element is inmovably connected to its surroundings.